In order to detect the impact of the negative bias temperature instability（ NBTI） effect on combinatorial logic path delay

a hybrid structure detection module for sensing the NBTI effect of the microprocessor core is designed. It includes mainly an aging delay detection module and a measurement module

which can measure the circuit delay caused by the NBTI effect accurately. Experimental results show that the area overhead is reduced by40 % compared to the traditional single delay line structure. The designed structure is tested on the ISCAS and OR1200 cores

and the delay measurement precision can reach more than 94 %

which can provide the fine-grained protection for the reliability design of microprocessors.